Typebar assembly

ABSTRACT

A typebar assembly for a typewriter is disclosed which includes a type font supporting element that is fixedly supported on the free end of a typebar by means of crossed recesses mating with the typebar and selectively detachable therefrom by a spring means. The rotatable type font element is a rectangular bar and has type font characters embossed on the opposite narrowmost faces of the element. The typebar is adapted to provide a support for the type element which, when seated on the typebar, is always oriented in a substantially parallel relationship with the conventional type elements in the typewriters and held against relative movement.

United States Patent 1191 Zeamer 1- Nov. 25, 1975 TYPEBAR ASSEMBLY [75] Inventor: Aaron C. Zeamer, Cortland, NY.

[73] Assignee: SCM Corporation, New York, N.Y.

[22] Filed: Jan. 2, 1974 [21] Appl. No.: 430,347

Primary Examiner-Edgar S. Burr Assistant Examiner-Paul T. Sewell Attorney, Agent, or Firm-Stanley Klern; Milton M. Wolson, Esq.

[57] ABSTRACT A typebar assembly for a typewriter is disclosed which includes a type font supporting element that is fixedly supported on the free end of a typebar by means 'of crossed recesses mating with the typebar and selectively detachable therefrom by a spring means. The rotatable type font element is a rectangular bar and has type font characters embossed on the opposite narrowmost faces of the element. The typebar is adapted to provide a support'for the type element which,when seated on the typebar, is always oriented in a substantially parallel relationship with the conventional type elements in the typewriters and held against relative movement. I

11 Claims, 7 Drawing Figures Sheet 1 of 2 US. Patent Nov. 25, 1975 US. Patent Nov. 25, 1975 Sheet20f2 3,921,783

TYPEBAR ASSEMBLY BACKGROUND OF THE INVENTION Previous concepts of detachable typebar assemblies included devices with inherent deficiencies.

One such concept teaches a typebar assembly with a typebar having formed guide slots at its uppermost portion to accommodate a type element assembly comprised of a multiplicity of parts of substantial mass. The type element assembly is rotatably mounted on the end of a carrier that, in turn, is detachably mounted to a typebar. The substantial mass of the typebar assembly is not conducive to high speed flying typebars in that the high mass of the type element traveling at a high inertial velocity, impacts a printing medium with greater force than a low mass type element. Consequently, characters typed with a type element of substantial mass are of greater density than characters typed with type elements of less mass and the result is a printed line of characters of various densities. Costly internal machine modifications would be necessary to counteract this adverse condition.

The disadvantages of the foregoing type element are overcome by the type element of the present embodiment having lightweight plastic construction and unitary design.

Another concept of a changeable typebar assembly teaches a cylindrical type element that is detachably mounted on the distal end of a typebar whereupon selected characters on the type element may be aligned for impact on a platen by selectively rotating the cylindrical element to a detented location. Disadvantages common to the previous concept mentioned are also prevalent in this concept, notwithstanding the fact that the element is manufactured from a synthetic resin. For example, the diameter of the cylindrical type element is of significantly greater dimension than the width of a conventional type element. Consequently the space requirements necessary to accommodate the type element at rest position are greater than that of a conventional type element. This additional space requirement necessitates the type element being positioned at the end of the typebar segment and at a distance from an adjacent typebar greater than the distance between two conventional typebars. This additional space requirement also requires machine width concessions or alternatively, the deletion of several typebars.

The slim silhouette of the present invention overcomes this disadvantage in that the typebar assembly may be positioned at any typebar location of the typebar segment without any alteration thereof.

Other typebar assemblies show a thin silhouette type element that is locked on the free end of a typebar. These embodiments overcome some of the disadvantages prevalent in the previously mentioned devices. For example, both are multipositional within a typebar segment due to their slim silhouette, and both are of low mass and therefore not susceptible to printing characters that are of greater density than the characters printed with a conventional non-detachable type element.

However, the type elements are not rotatable relative to the typebar and may become unseated from their locked positions due to centrifugal force during flight and fly off the end of the typebar.

The present embodiment is of an improved design in that a spring biased tongue and groove locking relationship positively precludes the type element from becoming unseated and flying off the typebar-during flight. In fact, the type element is more securely locked into engagement in the typebar by the centrifugal force effect on the type element forcing the type element toward the tongue and groove locking relationship.

SUMMARY OF THE INVENTION According to the present invention a typebar assembly for a typewriter is provided having a rectangular block type element detachably mounted on a typebar; the type element having type font characters embossed on the opposite narrowmost faces of the element. The type element has grooves of unequal depth oriented transverse of one another on an upper end of the type element and includes a spring seated in an aperture on a lower end of the type element. The deeper of the grooves provides installation clearance between the type element and a distal end (free end) of the typebar whereas the shallower groove cooperates with the distal end of the typebar to lock the type element in alignment relative to the distal end of the typebar and relative to the remaining conventional type elements thereby orienting a selected type face for striking against a platen (not shown). Means are provided to allow the type element to be rotated and present a second selected type face for striking against a platen.

Accordingly, it is an object of the present invention to provide a typebar assembly that can be easily removed and replaced.

Another object of the present invention is to provide a typebar assembly with a type element of minimum mass to lessen the centrifugal forces that the typebar assembly and related components are subjected to.

Another object of the present invention is to provide a typebar assembly of slim silhouette that can be installed in any position in a typewriter segment without modifications being made to the segment to accommodate it. V

A further object of the present invention is to provide a typebar assembly that, when in its operating position, is locked into engagement with the typebar and by utilizing the centrifugal force common to flying typebars to more securely lock the type element into engagement thereby precluding any flying-off of the type element.

Other objects, features, and advantages of the invention will become more apparent from the following description, appended claims, and accompanying drawmgs.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the typebar assembly showing the type element mounted to the typebar.

FIG. 2 is a perspective section view of the type element as shown in FIG. 1.

FIG. 3 is a perspective view of the distal end of the typebar.

FIG. 4 is a perspective view of a typebar and type element showing the type element in position preparatory to placing it on the typebar.

FIG. 5 is a perspective view of the typebar with the type element axially aligned with the typebar support lugs.

FIG. 6 is a plan view of the upper end of the type element.

FIG. 7 is an enlarged sectional perspective view of the type element assembled on the typebar.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGS. 1 and 7 showing the typebar assembly having a type element 10 locked into engagement with a typebar 12. The structure of the lower end of typebar 12 is common to that of most typewriters utilizing segment supported typebars. A distal end 14 of typebar 12, best shown in FIG. 3, is comprised of an upper arm 16 and a lower arm 18 attached to opposite ends of a base 20 to define a yoke 22. An integral lower lug 26 projects upward from the end of lower arm 18 and an integral upper lug 28 projects downward from upper arm 16 toward, and in co-axial alignment with lower lug 26. Lower lug 26 and upper lug 28 are of sufficient length and spaced from yoke base 20 a sufficient distance to allow type element 10 to be freely rotatable relative to the lugs when inserted or removed.

Upper arm 16 is provided with an extension 31 which extends beyond lug 28 for cooperating with the upper arm 16 to prevent rotation of type element 10 when type element 10 is locked into engagement with typebar 12.

Type element 10, preferably of plastic or any other suitable lightweight material, best shown in FIG. 2, is a rectangular block with its narrowmost faces and 32 providing the surfaces upon which selected characters 34- are embossed. An upper end 38 of type element 10 has a first groove 40 centrally located along the narrow width of end 38 and spans the distance between the faces 30 and 32. Groove 40 is of a width so as to slideably accommodate the thickness of upper member 16 and of such depth so that when type element 10 is positioned on the typebar 12 as shown in FIG. 1, the walls 60 and 62 of groove 40 of the type element engage the upper arm 16 to prevent rotation of type element 10.

A second groove 42 lies transverse of groove 40 and is of a greater depth than groove 40 so that when type element 10 is in an intermediate position as shown in FIG. 5, there is sufficient clearance between a base 44 of upper lug 28 and a base 46 of groove 42 whereby type element 10 may be pivoted out of alignment with upper lug 28 to permit removing and assembling type element 10 from and to typebar 12.

A blind aperture 48 is located on a lower end 50 of type element 10 and is in alignment with intersection point 52 of groove 40 and groove 42 of the upper end 38 of type element 10 as shown in FIG. 6 and provides frictional confinement for a compression spring 54 disposed therein.

Referring now to FIGS. 4, 5, and 1 showing the installation procedure for type element 10. Type element 10 is oriented as shown in FIG. 4 with the aperture 48 adjacent to lug lower 26. Type element 10 is then positioned with lower lug 26 inserted within aperture 48 and pivoted onto lower lug 26 until the type element 10 is substantially parallel to yoke base 20 at which time groove 42 is in alignment with upper yoke arm 16 and upper lug 28. Type element 10 is then manually pushed downward on lower lug 26 thereby compressing a spring 54 within aperture 48 until upper end 38 of type element 10 is clear of an inner edge 56 of upper yoke arm 16. With type element 10 held down on lower lug 26, type element 10 is rotated 90 about lower lug 26 and then released. Spring 54 extends within aperture 48 and urges type element 10 upward until groove 40 engages upper lug 28 and base 58 of groove 40 abuts inner edge 56 of upper yoke arm 16 at which time walls 4 60 and 62 of groove 40 are contiguous with the upper yoke arm 16, and arm extension 31 of typebar 12 to prevent further rotation of the type element 10 and to insure proper alignment of the type face 30 for print mg.

To align the type face 32 for printing, type element 10 is again manually pushed downward on lower lug 26 thereby compressing spring 54 within aperture 48 until the upper end 38 of type element 10 is clear of inner edge 56 of upper yoke arm 16 and upper lug 28 is disengaged from type element groove 40. As type element 10 is held down on lower lug 26, type element 10 is rotated 180 and then released. Spring 54, now extending within type element aperture 48 urges type element groove 40 into engagement with the typebar 12 for printing.

To remove type element 10 from the typebar 12 and replace it with an alternate element, the typebar element 10 is again pushed downward on lower lug 26 until upper end 38 of type element 10 is clear of inner edge 56 of upper yoke arm 16. The type element 10 is then rotated and then the type element 10 is tilted outward of yoke 22 and lifted free. An alternate type element may then be installed on the typebar 10 using the procedure mentioned above.

While the foregoing description has shown and described the fundamental novel features as applied to a preferred embodiment, it will be understood by those skilled in the art that modifications embodied in various forms may be made without departing from the spirit and scope of the invention.

What is claimed is:

l. A changeable type element carrying a type character on one face thereof for selective attachment to a yokeshaped distal end of a typebar having a pair of arms, the type element comprising:

a first groove formed in another face of said type element for receiving and confining at least a portion of one of the arms of said yoke-shaped distal end; and

co-acting means including an aperture formed in a face opposite said first groove having confined therein, a resilient biasing member, said aperture for receiving a portion of another of said pair of arms for abutting and compressing said resilient member for urging said type element into engagement toward said one arm when said type element is disposed in an operative position on said distal end intermediate the arms thereof.

2. The type element according to claim 1 wherein said type element is provided with a second groove in said another face and said second groove is transverse to said first groove.

' 3. The type element according to claim 1 wherein said first groove is formed with a step portion to provide an abutment therein.

4. The type element according to claim 2 wherein said second groove is deeper than said first groove.

5. A separable typebar assembly for business machines comprising in combination:

a typebar having a yoke-shaped distal end, said distal end including an upper arm and a lower arm, a lower lug extending from said lower arm and an upper lug extending from said upper arm;

a type element having a face with at least one character embossed thereon, means defining an aperture on an end for receiving one of said lugs, means defining a first groove and a second groove transverse to said first groove on another end for receiving the other of said lugs; and

means for urging said type element into engagement with said distal end for locking said type element on said distal end.

6. A separable typebar assembly as defined in claim 5 wherein said upper lug and said lower lug extend toward one another for spanning said type element ends for supporting said type element.

7. A separable typebar assembly as defined in claim 5 wherein said upper lug is in alignment with said lower lug and said type element aperture is in alignment with said type element recess for supporting said type element in a direction transverse to said embossed face.

8. A separable typebar assembly as defined in claim 5 wherein said urging means is a spring.

9. A separable typebar assembly as defined in claim 8 wherein said lower lug extends into said aperture for abutting and compressing said spring for urging said type element into engagement with and maintaining engagernent of said type element and said distal end.

10. A removable typebar assembly for business macnines comprising in combination:

a type element for carrying a type character on one face thereof and provided with a first groove and a second groove in one end thereof and an aperture in an opposite end thereof extending partially therethrough;

a typebar having a distal end formed for engaging said first groove for aligning and holding said type element relative to said distal end;

a spring confined entirely within said type element aperture between said distal end and said type element for maintaining positive engagement of said type element groove with said distal end;

a lower lug on said distal end of said typebar extending partially into said aperture of said type element 6 for abutting and compressing said spring for urging said type element into engagement with and maintaining engagement of said type element relative to said distal end; and

an upper lug on said distal end receivable by said second groove to disengage said first mentioned groove from said distal end to permit rotation of said print element.

11. A removable typebar assembly for business machines comprising in combination:

a type element for carrying a type character on one face thereof and provided with a first groove and a second groove in an upper end thereof and an aperture in a lower end thereof extending partially therethrough;

a typebar having a distal end that includes a yoke formed for engaging said first groove for aligning and holding said type element relative to said distal end; 7

a spring confined entirely within said type element aperture between said distal end and said type element for maintaining positive engagement of said type element groove with said distal ends;

a lower lug extending from one end of said yoke extending partially into said aperture of said type element for abutting and compressing said spring for urging said type element into pivotal engagement with and maintaining engagement of said type element relative to said distal end; and

an upper lug on said yoke projecting a fixed distance toward and in alignment with said lower lug for engaging said upper end of said type element for substantially spanning the type element for securely supporting the type element relative to said typebar. 

1. A changeable type element carrying a type character on one face thereof for selective attachment to a yokeshaped distal end of a typebar having a pair of arms, the type element comprising: a first groove formed in another face of said type element for receiving and confining at least a portion of one of the arms of said yoke-shaped distal end; and co-acting means including an aperture formed in a face opposite said first groove having confined therein, a resilient biasing member, said aperture for receiving a portion of another of said pair of arms for abutting and compressing said resilient member for urging said type element into engagement toward said one arm when said type element is disposed in an operative position on said distal end intermediate the arms thereof.
 2. The type element according to claim 1 wherein said type element is provided with a second groove in said another face and said second groove is transverse to said first groove.
 3. The type element according to claim 1 wherein said first groove is formed with a step portion to provide an abutment therein.
 4. The type element according to claim 2 wherein said second groove is deeper than said first groove.
 5. A separable typebar assembly for business machines comprising in combination: a typebar having a yoke-shaped distal end, said distal end including an upper arm and a lower arm, a lower lug extending from said lower arm and an upper lug extending from said upper arm; a type element having a face with at least one character embossed thereon, means defining an aperture on an end for receiving one of said lugs, means defining a first groove and a second groove transverse to said first groove on another end for receiving the other of said lugs; and means for urging said type element into engagement with said distal end for locking said type element on said distal end.
 6. A separable typebar assembly as defined in claim 5 wherein said upper lug and said lower lug extend toward one another for spanning said type element ends for supporting said type element.
 7. A separable typebar assembly as defined in claim 5 wherein said upper lug is in alignment with said lower lug and said type element aperture is in alignment with said type element recess for supporting said type element in a direction transverse to said embossed face.
 8. A separable typebar assembly as defined in claim 5 wherein said urging means is a spring.
 9. A separable typebar assembly as defined in claim 8 wherein said lower lug extends into said aperture for abutting and compressing said spring for urging said type element into engagement with and maintaining engagement of said type element and said distal end.
 10. A removable typebar assembly for business macnines comprising in combination: a type element for carrying a type character on one face thereof and provided with a first groove and a second groove in one end thereof and an aperture in an opposite end thereof extending partially therethrough; a typebar having a distal end formed for engaging said first groove for aligning and holding said type element relative to said distal end; a spring confined entirely within said type element aperture between said distal end and said type element for maintaining pOsitive engagement of said type element groove with said distal end; a lower lug on said distal end of said typebar extending partially into said aperture of said type element for abutting and compressing said spring for urging said type element into engagement with and maintaining engagement of said type element relative to said distal end; and an upper lug on said distal end receivable by said second groove to disengage said first mentioned groove from said distal end to permit rotation of said print element.
 11. A removable typebar assembly for business machines comprising in combination: a type element for carrying a type character on one face thereof and provided with a first groove and a second groove in an upper end thereof and an aperture in a lower end thereof extending partially therethrough; a typebar having a distal end that includes a yoke formed for engaging said first groove for aligning and holding said type element relative to said distal end; a spring confined entirely within said type element aperture between said distal end and said type element for maintaining positive engagement of said type element groove with said distal ends; a lower lug extending from one end of said yoke extending partially into said aperture of said type element for abutting and compressing said spring for urging said type element into pivotal engagement with and maintaining engagement of said type element relative to said distal end; and an upper lug on said yoke projecting a fixed distance toward and in alignment with said lower lug for engaging said upper end of said type element for substantially spanning the type element for securely supporting the type element relative to said typebar. 